Bulb holders for use with printed circuit boards



BOARDS Aug. 12, 1969 w. L. F RY FOR USE WITH PRINT ED CIRCUIT BULB HOLDERS Filed April 11, 1967' United States Patent US. Cl. 33917 1 Claim ABSTRACT OF THE DISCLOSURE A bulb holder including a resilient conductive substantially Z-shaped strip one end of which is secured in contact with a first conductive area on a printed circuit board whilst the other end is shaped to engage the conductive cap of a bulb. The strip supports the bulb and urges a contact carried by the cap of the bulb, into engagement with a second conductive area on the board.

This invention relates to bulb holders for use in making an electrical connection from a printed circuit board to a bulb of the kind having one of its electrical connections made through a conductive cap and a second connection made through a contact carried by but insulated from the cap.

According to the invention a bulb holder for use with a bulb of the kind specified comprises a first portion secured to a printed circuit boa-rd and in electrical contact with a first conductive area on the board, and a second portion supported by and electrically connected to the first portion and spaced from the board, the second portion being shaped to engage said conductive cap and support the bulb with the contact carried by the bulb engaged with a second conductive area on the board.

One example of the invention is illustrated in the accompanying drawings wherein FIGURE 1 is a plan view of part of a bulb holder, FIGURE 2 is a side elevational view of the part shown in FIGURE 1, FIGURE 3 is a plan view of a plurality of bulbholders and FIGURE 4 is a side elevational view of the arrangement shown in FIGURE 3.

Referring firstly to FIGURES 1 and 2 the bulbholder 11 includes a Phosphor bronze strip 11a having two substantially parallel portions 12, 14 interconnected by a leg portion '13 which is generally at right angles to the portions 12, 14. The portion 14 has a hole 15 therein and terminates at its free end in a pointed projection 16 which is inclined in the opposite direction to the leg portion 13. The portion 12 is generally square and has a centrally disposed hole 17 of diameter substantially equal to that of the overall diameter of the screw threaded cap of a bulb to be supported. The portion 12 is also formed with a small slot 18 which breaks the periphery of the hole 17. The portion 12 is deformed around the hole 17 so that the periphery of the hole 17 defines one convolution of a screw thread, of substantially the same pitch as the screw thread of the bulb.

Referring now to FIGURES 3 and 4 a plurality of strips 11a are secured, in spaced relationship, to a printed circuit board 21, by rivets 22 which extend through the holes 16 in the strips 11a. The portion 14 of each strip 11a is in contact with the board 21 and the arrangement is such that the pointed projection 15 of each strip pierces the surface of a conductive area 23 of the board, thereby making a good electrical contact thereto, and furthermore prevents rotation of the strip 11a about its rivet 22. The portion '12 of each strip 11a overlies a further conductive area 24 of the board so that when a bulb is 3,461,418 Patented Aug. 12, 1969 "ice screwed into the strip the contact on the base of the bulb engages the second conductive area 24 of the board, so that the conductive areas 23, 24 of the board 21 are electrically interconnected through the bulb. It will be appreciated that by virtue of the resilience of the strips of Phosphor bronze the bulbs are urged towards the board 21, thereby ensuring a good electrical contact between the contact on the cap of each bulb and the respective area 24 of the board 21.

Electrical connections between the areas 23, 24 and the required external circuits are made through the intermediary of pins 25 which project through the board and the respective conductive area, and have their ends peened over in the same manner as the rivets 22 into contact with the respective conductive area. The periphery of the board 21 includes a slot 26 which is engaged by a corresponding rib on a housing in which the board 21 is supported, thereby ensuring correct alignment between the bulbs and a plurality of coloured filters carried by a cover associated with the housing. Furthermore adjacent each of the strips 11a the board 21 is provided with means 27 for identifying the circuit associated with each of the strips 11a so that should one of the bulbs fail, an operator can easily identify the faulty bulb when the cover associated with the housing is removed.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A bulb holder, for use with a bulb of the kind having one of its electrical connections made through a conductive cap having a screw thread thereon and a second connection made through a contact carried by, but insulated from the cap, comprising a printed circuit board, first and second exposed, conductive areas on the board, a resilient conductive strip having a first portion rivetted to said printed circuit board, a projection integral with said first portion of the strip, said projection piercing the surface of said first conductive area and thereby electrically connecting the strip to said first conductive area and resisting angular movement of the strip relative to the printed circuit board, a second portion of said strip spaced from said printed circuit board and supported by said first portion of said strip, said first and second portions of the strip being electrically interconnected, an aperture in said second portion of said strip, and a screw thread defined by the periphery of said aperture, said screw thread being of similar dimensions to the screw thread on the cap of said bulb, said second portion of said strip being disposed above said second conductive area, and the arrangement being such that, in use engagement of the screw thread on the cap of said bulb with the screw thread on said second portion of said strip serves to electrically interconnect the cap of said bulb and said first conductive area, and said strip supports said bulb with said contact engaged with said second conductive area so that a circuit between said first and second conductive areas is completed through said bulb, the resilience of said strip maintaining said contact in engagement with said second conductive area.

References Cited UNITED STATES PATENTS 1,719,284 7/1929 Barnes 339-17 2,736,876 2/1956 Gerbracht 339-17 XR 2,972,727 2/19'61 Flanagan et a1. 3,344,388 9/1967 Parker et a1.

FOREIGN PATENTS 1,089,224 9/ 1954 France.

MARVIN A. CHAMPION, Primary Examiner PATRICK A. CLIFFORD, Assistant Examiner US. Cl. X.R. 339-95, 199, 220 

